This invention relates to a circuit arrangement for supplying a load with energy from a power supply mains.
German Patent Application P 37 22 337.2, to which U.S. Pat. No. 4,821,166 corresponds, describes a circuit arrangement for transferring electric power to a load from an alternating voltage source which is connected during given time intervals to an energy storage device for the purpose of supplying it with energy. The arrangement includes a switch which is periodically activated by a control circuit for deriving the energy for the load from the energy storage device. In this circuit arrangement high frequency disturbances produced therein are suppressed, i.e. kept away from the alternating voltage source, in that the control circuit renders the switch conductive only in time periods outside of the time intervals in which the alternating voltage source is connected to the energy storage device. This arrangement is particularly used especially in switchedmode power supplies which derive energy from a mains alternating voltage thereby generating interference voltages and currents due to the switching processes of the periodically activated switch, which interference voltages and currents should not be introduced into the mains alternating voltage. The connection or separation of the alternating voltage source and the energy storage device is preferably effected by a rectifier stage. In the time intervals in which the rectifier stage is in the conducting state for the purpose of recharging the energy storage device, the activation of the switch is interrupted so that this switch does not introduce any interference via the conducting rectifier stage into the alternating voltage source, i.e. the mains.
However, interrupting the activation of the switch also interrupts the supply of energy to a load which is fed by the switched mode power supply so that this load is periodically and not uniformly supplied with energy.